Media Area 25 sq ft, 4 15/16" OD, Open Hole: 2 1/8" Top, Open Hole: 2 1/8" Bottom, 13 5/16" Long, AK-3047 1 Year Warranty - Baleen Filters are made from Durable and Efficient USA Made Reemay Fabric - Washable Fabric Extends Your Filter's Life 25 sq. ft. In-Line Filter for Dynamic Series I RDC-25, RDC-25S, Dynamic Series II RTL/RCF-25, Dynamic Series III RTL/RCF-25, replacement of Unicel C-4625, Pleatco PRB25-IN-4 Baleen Filters Top: Open Hole: 2 1/8" Bottom: Open Hole: 2 1/8" Guaranteed Perfect Fit - Extremely Durable - Wash & Reuse - Most Energy Efficient - Withstands High Pressures & Temperatures 25 sq. ft. In-Line Filter for Dynamic Series I RDC-25, RDC-25S, Dynamic Series II RTL/RCF-25, Dynamic Series III RTL/RCF-25, replacement of Unicel C-4625, Pleatco PRB25-IN-4, Compatible with Alps Spas, Aries Spas, Associated Leisure Products, Blue Pacific Spas, Esther Williams, Haughs, Heldor Spas, Hydro Pool Industries, J.E.M. Spas, Niagra Whirlpool, Pentair Pool Products - Rainbow Plastics Replacements, Sequoia Design, Serenity Spas, Warm Springs Spas, Waterway Plastics Our Universal Pleated Filter Cartridges are washable, reusable, and durable. As a result, our filters last longer than other brands, and are more economical too. Our filters work hard for you by holding more dirt than other brands; and increased dirt holding capacity means cleaning your pool or spa less often. Our universal pleated filter cartridges are constructed of the highest quality non-woven polyester, with a durable polypropylene core to provide maximum strength.